It is well known at the present time to provide an apparatus capable of shredding documents which can be of various types including foil, sheet and strip material. The material can also differ and can be, for example, paper, plastic or the like. At the present time, one important type of document to be shredded consists of plastic strips and tapes of various kinds including magnetic tapes, microfilm strips, and other similar articles.
Large quantities of the aforementioned documentary materials are obtained at different places and, for various reasons, must be destroyed. These reasons include the maintenance of secrecy but also include the fact that the material has become superceded or out of date. However, it is necessary for destruction to take place in such a way that the "destroyed" documents would not yield any useful information if they fell into unauthorized hands.
A particularly reliable way of insuring that no information can be gathered from the documentary material consists of making it unusable by shredding it into very small pieces. For this purpose, various structures have been devised which shred the documents into more or less small shreds. In one known structure, shown in U.S. Pat. No. 4,200,239, a high-speed rotor is used which is equipped with one or two rows of teeth which cooperate with a fixed serrated member. In order to achieve good shredding action, the teeth of each row are constructed at different heights in an alternating manner. The serrated member is also formed in a scalloped manner to conform with the tooth sequence. In order to achieve uniform shredding of the documents, a delivery support is provided on which is arranged a feed roller. The function of the feed roller is to uniformly move the sheet, strip or other documentary material against the rotating teeth of the rotor. However, if the feed is not correctly set with respect to the rotor speed in this known structure, clean separation of the documents into individual portions does not result. The reason for this is that the feed of the documents per tooth row is greater than the radial spacing between the tips of the teeth of the larger and smaller teeth in each row. If this occurs, the unequally long teeth are no longer able to separate individual shreds from the supply document and, instead, cut a scalloped strip which is continuous over the axial length of the rotatable cutter. This is an undesirable result because it no longer guarantees the destruction of the information on the documents.
Thus, in this known structure, it is necessary to check the feed and ensure that it correctly functions in such a way that there are no continuous shreds in the axial direction of the rotor. This makes the apparatus more complicated because a feed device must be provided in each machine.